Papers by Keyword: Argon Gas

Abstract: Solar cell converts sunlight into electricity with no moving parts and environmental friendly. Although silicon based solar cell is currently more efficient, the dye-sensitized solar cell is considerably cheaper to manufacture because of its low cost materials and simplicity process of fabrication. In this paper, the development of plasma formed equipment for thin film material on flexible solar cell using low-pressure high frequency Plasma Chemical Vapor Deposition method on the surface of Polyethylene naphthalate (PEN) with the mixture of Ar gas and N₂ gas is presented. The results indicate that using this method can be possible for surface modification.

Abstract: The differences in structural, compositional and photoelectrochemical properties for SnSe films annealed at different temperatures, under nitrogen atmosphere, were studied. Annealing the film electrode significantly improved its crystallinity but lowered its photoresponse. The photoresponse lowering was thus attributed to lowering in the defect concentrations.

Abstract: The Emission Characteristic of Copper Ionic Lines Requiring Large Excitation Energies Was Investigated in Low-Pressure Laser-Induced Plasma Spectroscopy (LP-LIPS), when Argon Was Employed as Plasma Gas. The Excited Mechanism of the Ironic Lines Whose Electron Transitions Were Assigned to the 3d⁹5s-3d⁹4p Configuration Was Understood from the Time-Resolved Spectra of Copper. The Emission Intensity of the Copper Emission Lines, Measured in a Time-Resolved Mode, Was Extremely Dependent on the Kind of Copper Lines and the Upper Energy. Generally, their Emission Intensities Dramatically Decreased with the Duration Time, along with the Recombination as Well as the De-Excitation of Copper Ions Requiring Larger Kinetics Energy which Mainly Were Produced in a Hot Breakdown Plasma. The Emission Behavior Excited from the 3d⁹5s-3d⁹4p Transition, such as the Cu II 254.4 nm and the Cu II 276.9 nm Lines, Was Generally Similar to that from 3d⁹4p-3d⁹4s Transition, although their Excitation Energies Were Different. This Effect Would Result from a Common and Dominant Ionization /excitation Mechanism, which Was Collision Energy Transfer from Energetic Particles such as Fast Electrons.

Abstract: Diamond tools wear easily under cutting tungsten carbide. To clarify the wear mechanism, the authors composed a temperature-measurement system of a cutting point using a dual-colorinfrared pyrometer and performed planing experiments. Infrared rays, emitted from the contact point between a mono-crystal-diamond tool and a cobalt-free tungsten carbide, are transmitted though the diamond tool and an optical fiber and then they are detected by the pyrometer. Before the planing experiments, rubbing experiments were performed using a mono-crystal-diamond stick and a tungsten-carbide disk. The effects of gas environments and rubbing conditions on contact-point temperature, friction coefficient, and diamond wear were experimentally investigated. Planing experiments of the tungsten carbide using mono-crystal-diamond tool, were performed. The effects of planing conditions and gas environments on cutting-point temperature and tool wear were investigated. Through the experiments the following results were obtained. Rubbing and cutting point temperature is the highest in Argon gas followed by Nitrogen gas and is the lowest in Air. Diamond-tool wear is the greatest in Argon gas, less in Nitrogen gas, and the least in Air. The reason for this is that a chemically or physically absorbed layer of oxygen or nitrogen on tungsten carbide acts as a lubricant at the contact point. Cutting-point temperature was in proportion to cutting speed. The temperature under cutting speed at 90m/min and cutting depth at 1.0μm in Air was approximately 170degrees Celsius.

Abstract: Diamond coatings on pure titanium substrates are of interest for tribological and biomedical implants. However, due to the different thermal expansion coefficients of the two materials, the complex nature of the interlayer formed during diamond deposition, and the difficulty in achieving very high nucleation density, it is hard to deposit adherent thin diamond layers on titanium. The aim of the present research was to successfully produce smooth and well adherent nanocrystalline diamond (NCD) film on a pure Ti substrate using the microwave plasma chemical vapor deposition (MWPCVD) method. The influence of Argon addition to CH4/H2 plasma on the crystallinity, morphology and growth of the diamond film deposited by MWPCVD was investigated using field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), Xray diffraction (XRD) and Raman spectroscopy.